textproduct: Albany

WHAT HAS CHANGED

No major changes to the forecast.

KEY MESSAGES

1) There is a marginal risk (Level 1 of 5) for isolated severe thunderstorms in the western Adirondacks this afternoon into early this evening. Primary hazards are strong winds and heavy downpours.

2) Heat and humidity today will result in minor to locally moderate heat-related impacts. After a break from the heat this weekend, confidence is increasing in another period of above normal temperatures early to mid next week resulting in minor to moderate heat-related impacts.

DISCUSSION

KEY MESSAGE 1...

A weak pressure trough tracking eastward out of southern Canada into NY this afternoon into the evening combined with weak height falls ahead of broad troughing over the Great Lakes will help initiate isolated to scattered showers and thunderstorms. Latest CAMs continue to show two distinct areas of activity. The first is focused mainly from the Capital District north and west into the southwest Adirondacks associated with the incoming pressure trough and weak height falls. Then, there is a second area mainly in eastern PA and NJ/southern NY that may graze our mid- Hudson Valley and NW CT areas as mid-level shortwaves and a subtle boundary lift northward. Despite the warm/humid conditions, instability is unimpressive generally under 1000 J/kg due to warm temperatures aloft and forecast soundings showing a weak capping inversion. Even still, CAMs show showers and storms initiating mainly near or shortly after 18 UTC through 03 UTC; however, given weak forcing, coverage is isolated/scattered. With deep layer shear ranging 20 to 30kts and 850-300hPa lapse rates 5.5-6C/km, SPC continues to graze our western Adirondack areas in a marginal risk (level 1 of 5) for isolated severe storms today where the best height falls are expected. Damaging winds and heavy downpours remain the primary hazard from any severe storm. Elsewhere, severe weather is unlikely.

KEY MESSAGE 2...

We start off the day with weak ridging overhead as high pressure from yesterday slides off the East Coast. With broad troughing positioned well upstream in the Great Lakes, we will enter into a southwest flow regime supporting weak warm air and moisture advection resulting in temperatures climbing a few degrees higher than yesterday into the mid to upper 80s with probabilistic guidance showing a 40 to 70% chance for valley areas to reach or exceed 90 degrees. Given elevated humidity levels, heat index values or the "feel-like temperatures" will near 95 degrees in these areas; however, given the limited coverage with the HeatRisk mainly in the minor to moderate range, we continue to hold off on heat advisories for today. Regardless, it will still be very warm and humid today so avoid strenuous outdoor activities and drink water even if you are not thirsty. Tomorrow will not be as warm given increased cloud coverage and showers and a few storms as a cold front pushes through the region.

After a break from the heat and humidity this weekend, there is a growing consensus among the medium and long range guidance for a period of above normal temperatures returning early to mid next week. This comes as a heat dome in the Central Plains slides eastward resulting in 850hPa isotherms ranging 2 to nearly 3 standard deviations above normal per the ENS next Monday through Wednesday. Latest probabilistic guidance from the NBM shows a 50 to 75% chance for high temperatures to reach or exceed 90 degrees across much of eastern NY and western New England (outside of the high terrain) with even a 25 to 50% chance for reaching or exceeding 95 degrees. There remains some uncertainty with how long the heat will last as there is decent consensus for a trough from southern Canada to track south/eastward into the Northeast late next week. This would help shift the heat out of our area but also increase the chance for severe weather. The SPC Day 4-8 outlook continues to discuss the potential for severe weather for the middle of next week in the Northeast while also outlining uncertainty in the exact location.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Through 18z Friday...VFR conditions prevail across all terminals this afternoon with visible satellite showing some agitated cumulus across eastern New York and western New England. Modest instability ahead of an incoming wind shift boundary which could support some isolated to widely scattered showers and potential thunderstorms late this afternoon into this evening. The best chances for thunder fall between 22-04z, so PROB30s were added to the TAFs accordingly. KPOU was the only exception to this, as probabilities for even showers look to be fairly low here. Any thunderstorms that develop look to reduce conditions into at least the MVFR category, though, outside of PSF where MVFR ceilings may linger for a while, VFR conditions should swiftly return after their conclusion. Variable winds this afternoon will ultimately switch to a largely northeast direction by the end of the period with sustained speeds generally under 10kt outside of thunderstorms throughout the duration of the 18z cycle.

Outlook...

Friday Night: Low Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.